Telephone-transmitter



No. 623,908. Patented Apr. 25, I899.

E. H. JOHNSON.

TELEPHONE TRANSMITTER.

(Application filed May 9, 1898.) (No Model.) 2 Sheets-Sheet l.

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No. 623,908. Patented Apr. 25, I899. E. H. JOHNSON.

TELEPHONE TRANSMITTER.

(Application filed my 9, 1898.)

(No Model.) 2 Shoots-Sheet 2.

WITNESSES MI MN 70/? A TTOHNE Y8.

THE NORRIS PETERS 0o. FHOTD-UTHQ, WASHINGTON, n. c.

EDWARD II. JOHNSON, OF OMAHA, NEBRASKA.

TELEPHONE-TRANSMITTER.

SPECIFICATION forming part of Letters Patent No. 623,908, dated April 25, 1899. Application filed May 9, 1898- Serial No. 680,195. (No model.)

To all whom, it may concern:

Be it known that I, EDWARD H. JOHNSON, of Omaha, in the county of Douglas and State of Nebraska, have invented a new and Im proved Telephone-Transmitter, of which the following is a full, clear, and exact description.

This invention relates to improvements in electric-telephone transmitters; and the object is to provide a transmitter so constructed that the sound impulses against the diaphragm will be multiplied, and consequently increased in the receiver.

I will describe a telephone-transmitter embodying my invention and then point out the novel features in the appended claims.

Reference is to be had to the accompanying drawings, forming a part of this specification, in which similar characters of reference indicate corresponding parts in all the views.

Figure 1 is a sectional elevation of a transmitter embodying my invention. Fig. 2 is a sectional elevation showing a modification. Fig. 3 shows another modification, and Fig. 4 shows a contact-supporting device.

Referring first to the example of my improvement shown in Fig. 1,' 1 designates a casing having a mouthpiece of any suitable form, such as shown at 2 or as shown by the dotted lines. Arranged within the casing is a frame 3, on which carbon contacts 4, 5, and 6 are secured. Bearing against the diaphragm 7 of the mouthpiece is a ring 8, of resilient materialsuch, for instance, as glass, metal, rubber, or the like. A strip 9, of membranous or similar flexible material, bears upon the ring at three points-that is, at points opposite the contacts 4, 5, and 6, and affixed to the strip and bearing upon said contacts are carbon contacts 10, 11, and 12. The strip 9 may be extended around rollers 13, by means of which the tension may be adjusted.

The respective contacts 4, 5, and 6, which may be termed the positive contacts, are connected by wires 14 15 16 to batteries 17 18 19, which also have connection with a return or ground wire 20. The negative contacts 10, 11, and 12 are connected, respectively, by wires 21, 22, and 23 with a line-wire 24. As the pressure of the diaphragm vibration forces the ring to expand equally in all directions, and as the amplification of sound depends greatly upon the contact-pressure in a transmitter, it will be seen that by this described arrangement of parts, the pressure being exerted at three points, the said contact will be threefold, and consequently a corresponding effect will be produced at the receiver.

In Fig. 2 I have shown means whereby the contact-pressure may be still more exerted. In this example there are three rings 25, 26, and 27. These rings are of resilient material, and the outer rings are attached to the center ring in any desired manner. The center ring 25 bears againstadiaphragm 28, and engaging at three points upon the rings 26 and 27 and at one point upon the ring 25 is a strip 29 of membranous material. The ends of this strip 29 are attached, respectively, to hooks 3O 31, extended inward from a casing 32, and the strip extends around pins 33, arranged in the casing. Its tension may be adjusted by lugs 34 in the casing.

Attached to the strip 29 at the points of its contact with the ring 25 is a carbon contact 35, which is in engagement with the carbon contact 36, attached to the frame. Also attached to this strip 29 at the point of its con nection with the ring 26 are contacts 37, 38, and 39, which engage, respectively, with contacts 40, 41, and 42, attached to the casing. The strip 29 is also provided at its points of connection with the ring 27 with carbon contacts 43, 44, and 45, which connect, respectively, with contacts 46, 47, and 48, attached to the casing. The contacts attached to the casing may be mounted on screws 49 for the purpose of adjustment. In this example it will be seen that there are seven points of contact, making the transmitter particularly useful in long-distance telephoning.

In Fig. 3 I have shown a series of rings 50, 5], 52, and 53 concentrically arranged one Within an other. These rings are of course of resilient material, as before described, and they are connected together at one side by a post 54, which bears against a diaphragm 55. The ring 50 is provided with three carbon contacts 56, 57, and 5S, engaging, respectively, with contacts 59, 60, and 61. The ring 51 is provided with three carbon contacts 62, 63, and 64, bearing, respectively, upon the positive contacts 65, 66, and 67. The ring 52 is provided with three contacts 68, 69, and 70, bearing, respectively, on positive contacts 71,

72, and 73, and the ring 53 is provided with contacts 74, 75, and 71 bearing, respectively, against positive contacts 77, 7S, and 79. The several positive contacts of a row may be supported on arms 80, ad justably connected to a bar 81. I have shown one arm 80 as having a shank portion extended through a slot in the support 81 and a screw 82 as engaging in a tapped hole in said shank and also engaging lugs extending from the support. By this means the several positive contacts may be adjusted relatively to the negative contacts.

It is obvious in this example that the vibrations of the diaphragm will set the several rings in equal vibration and the impulses will be greatly multiplied through the contacts.

Having thus described my invention, I claim as new and desire to secure by Letters Patent- 1. A telcphone-transmitter, comprising a diaphragm, a ring of resilient material bearing against said diaphragm, a series of contacts on said ring, and another series of contacts with which the first-named contacts engage, substantially as specified.

2. A telephone-transmitter, comprising a diaphragm, a ring of resilient material bearing against said diaphragm, a band or strip of flexible material engaging at different points on the ring, carbon contacts connected to such flexible material at its points of connection with the ring, and other carbon contacts engaging with the first-named carbon contacts, substantially as specified.

3. A telephone-transinitter, comprising a diaphragm, a ring bearing against said diaphragm, and a contact-point actuated by the varying pressure of the ring imparted by the varying vibration of the diaphragm to bear with varying pressure against another contact, substantially as specified.

4. A telephone, comprising a diaphragm,a ring of resilient material bearing again st said diaphragm, a band or strip of flexible material bearing at various points on said ring, means for varying the tension of said strip, con tact-poi nts mounted on the strip,and other con tact-points with which the first-named contact-points engage, substantially as specified.

EDXVARD H. JOHNSON.

Witnesses:

R. S. NEELY, F. .T. MoDoNALD. 

